Question: Why in verse John 18:14 does Caiaphas advise the Jews that it would be good if one man died for the people?
Answer: Caiaphas believed that Jesus was a threat to the commonwealth of Israel because he was claiming to be the Messiah. Several others had made similar claims in recent years and tried to start rebellions against Rome. He felt that Jesus might stir up the Romans to clamp down even tighter on Israel and this would be a threat to the high priest’s authority and a challenge to the effectiveness of his influence.
From God’s perspective it was good for one man, the God-Man Jesus, to die for (the sins of) the people that they might be redeemed from divine retribution. God’s wrath rests on all who follow their own ways and the only means of forgiveness is for someone to pay the penalty for our disobedience. That is what Jesus’ death accomplished.